Joseph b



Srucllwre uf Funnace. Haak olbaorbeul- Amis.

- yI :T

N. PETERS, PHDTO-LITHOGRAFHER. WSDUNGTON. D C4 titiirt' tritt' "and dnn Aany suitable construction, and canse the said air to 'their sensible, but of their 'latent heat, so as to feed thetire with air elevated to between 500O and 1,0000,

the planes of ascending cold air, and become so thor- Josnru n. BUCHANAN, or

Louisvittn, nnnrucur.

Letters Patent No. 113,250, dated April 4, 1871 antedated March 21, 1871.

IMPROVEMENT IN THE MANUFACTURE OF SALT.

I The Schedule referred to hi these Letters Patent and making part of the same.

I, J osnPH R. BUCHANAN, of Louisville, inthe coun ty of J eerson-and ,State of Kentucky, have invented certain new and useful Improvements in the Mannfacture of Salt, of which the followingis a specification.

The improvements V,embraced in this y specification relate to the manufacture of salt by boiling, and they are properly but .parts ofimy invention, which might have been embodied in my `patent of July, 1870, but which, on account of their extent 'and multiplicity of details, were not introduced in 'connection with the fundamental invention of which theyjare co-'operative parts, all important to be known and understood by those whol undertake to mamifacturesalt under my plans.

First, thel economy and eiiciency of the furnace.

Second, the elicient and complete removal of salt from the boilers and prevention of incrustation.

Third, variations in the forms, arrangement, and` connections of the boilers, desirable under different Amodes ofusing and'comliiniug them for dilerent brines, dilierent pressures, and other circumstances, and necessary to the completeness of the invention.

l. The Furnace.

I propose touse that style of regenerative furnace which Ihave ascertained to be the best for the economical'applcation Vof caloric. y

I surround the furnace (Figure 1, sheet l) with a layer of sawdust or other good non-conductor, as heretofore mentioned, inclosing it with tin-plate, Russia iron, wood,`or other suitable exterior.

I then supply the air of combustion by a blower of pass through the products of combustion which are escaping from the furnace, and rob them, not only of or even higher in 'some cases.

This is etfected by compelling the products of coinbnstion to descend in Avery narrowchannels between oughly cooled that all 'the vapor is condensed, gives up its latent heat,-and escapes by discharge as water- The amount of caloric thus saved which is usually 'wasted would be not less than six million (6,000,000) lequivalents (asdeiined by Joule and others) for every ton of coal, and the amount recovered by condensation (coal beingthe fuel) would be six hundred (600) cquiv. alents for every pound of coal.

These results may be attained by several forms of apparatus, and Ipropose two lorms as `being the best In the tirst, Figures 1, 2, 3, sheet l, 'the smoke,-A

ascending in Va central narrow channel 'orattened flue,ff, passes out' 0n each side, and descends through the smoke-channels hs 0s, entering as hot smoke and Vleaving as cold smoke, discharged linally by the exterior chimney ch.

These smoke-passages are formed by combining a corresponding number of attened air-channels ac ac,

lhg. 3, sheet l, which may be compared to tubes live conveying the air from an air-chamber below, ca ca,

where it tirst enters cold from the blower to an airchamber above, ha ha, where it is well heated from its passage upward through the narrow channels.

The smoke-boxes or main body ,of the apparatus, the cold-air chamber below, the hot-air chamber above, and the flattened channels that connect these hot and cold-ail' spaces, constitute nearly the whole structure.

We have only to 'add that thc hot air from ha lut descends through the middle of the iiattened liuc ff by a ilattened channel, ha ha, and is conducted by pipes or fines down the walls of the furnace to discharge the hot air under the grate and supply the lire with oxygen, being forced through it hy the pressure ofthe blower; and this pressure continuing through the iire, forces the smoke up its flattened liuc, and then down the smoke-passages between the air-channels, aud out at the chimney` or chimneys 0h, robbed of its heat.

A practical advantage of this structure is that it is so easily taken to pieces and cleaned or repaired.

The air-channels being attened tubes with their ends lared out like a flange, are set up togetherby being simply inserted in a rack or grate-frame at the top, and in like manner at the bott-om, the ared or tightly all around, either side may be opened at any time, and, by opening the side door s d and loosening the grate-frames, the air-channels may be taken ont. In the above structure the bottom grate-frame o o o, which compresses and holds'the anges of the air channels, should be hollowed out on its upper surfaces, so as to receive aml convey off the water of condensation from the smoke-passages and deliver it to the smoke-receptacle sr, from which the chimney ch takes the smoke, and the cock co discharges the water.

With some species ot' fuel, especially wood, the amount oi vapor in the products of combustion is too great to admit of its being condensed by the incoming air, and iirtliat case the discharged smoke should be i' ciducted through l pipes in a brine-vat, to heat the fresh brine, o'r be utilized by throwing it into the steam-spaces of the vacuum evaporator. v

The free combustion produced by the ample supply of air diminishes the amount of soot that would be formed in such au apparatus, and the rapid motion of the smoke contributes to keep it clear.

In the other structure, Figure 4, sheet l, a blower impelsthe cold air through ascending channels parallel to the descending smoke, and then down the main tlne M F, through pipes which -finally deliver the hot air at the grate of the furnace.

.Lhe cold air goes iirst to the circular channel 1,'

from which it ascends in a circle exterior to the circle of descending smoke, and as the latter reaches the level of the entering air itis cooled and its moisture precipitated, which is discharged by the cock co, while the cold smoke is forced up the chimney ch.

The simplest description ot' thisstructure isy to state that the main tlue or chimney MF rising from the tire has an exterior-f cyl-inderor cap, closed above,

slipped over it like a sleeve, with a space of an inch or more between them, down which the smoke is cornpelled to descend-until it reaches the circular receptacle c s, from which it is discharged by the outer chimney.

Exterior to this cylinder or sleeve is another just like it, o c, connectedI with it as one structure, and between these two the cold air ascends, heat-ed by the interior cylinder as it passes, until, arrested at the upper end, it is driven down through the descending pipes ha ha, in the main flue above the fire, and, heilig delivered into a circular receptacle., 3, passes therefrom, by pipes orchannelsbp, to the bottom of the grate.

An ekterior investment or casing of non-conducting materials should be added, -to inclose the entire beatabsorbent structure. l

The discharge of' the condensed steam from this apparatus is easily made by; opening a cock in the receptacle cs.

To perfect the condensation it will be necessary that the main tlue'M l" should be substantially constructed of ubu-coiuluctiug materials, so as .not to impart to the descending smoke thc heat ofthe interior ascending current. A double case of Russia iron, with felt, sawdust, or similar non-conductors interposed, would answer.

This structure will be easily cleaned by lifting the cylinders, which may be jointed like a stove-pipe.

In a furnace provided with this heat-absorbent apparatus the heat, if not absorbed rapidly by the boiler, rises rapidly to a grcatintensity. and a pyrostatic liquid, which will not produce much pressure at high temperatures, and which hasy great power of carrying caloric, is a desideratum,` I propose for this purpose a saturated solution of caustic soda or'l'mtassa, preferring the former, which will carry, almost without pressure, a temperature approximating a red heat. 'I

conveyed is equal to that of a correspoudingrmass of red-hotiron.

The high temperature of the products et'I combustion iu such an apparatus, where the heat is not very portions oi the heat-absorbent apparatus nearest to the ircvshould be constructed ot' enameled iron, firestance, to endure the hea-t.

Salt Collecting.

When brine is evaporated in close boilers the removal ot' the salt from its incrustation on the evaporating-surfaces and its deliveryfrom the boiler are matters of the highest importance. 1n my tirst plan-s, as4 recorded in my caveat, I relied upon the length ot the ebullition-current thereby produced, which was separated from the descending current by a central partition or cylinder, through which the brine descended, carrying down thel salt. method, and I now propose to enlarge and vary the methods to be adopted, so as to meet all emergencies or diculties.

rIhere are but three methods by which the removal of incrusting salt from evaporating-surfaces may be effected, viz:

First, by positive mechanical force, as by scraping or brushing Second, by fluid currents, each of which methods requires peculiar devices for its application; and

Third, by solution, which requires combined boiler arrangements.

M echan'iccl Force.

This may be most conveniently applied by revolving-Scrapers or brushes continually passing 4over the evaporating-suraces.

' A reciprocating scraper or brushmay also be used, especially when the evaporating-surlaces are tubes.

The scraper ina-y be propelled by an externalforce, or may be arranged to be moved by the currents ot' cbullition in the brine, as in 3, sheet 2.

A shaft running the entire length ot' the boiler may be armed with scrapers, extending out to touch its internal suri'ace. l

The plane'o' the scraper should be at an acute anglo to the plane of its revolution, so that it would throw the scraped substance to one side likea plow, and the scrapers should follow each other in a spiral manner, Figul'e, sheet 2, so that each, advancing a little further, would carry the substance gradually to one end ot' the boiler. as by a screwing movement.

The edge ofthe scraper may be a plate oi' thin metal, a wire brush, or any elastic substance that would apply a moderate friction, with a hard substance at its end.

.When the scraper is to be propelled by the force of ebnllition armsl should be extended from the shaft, (between the spirals) and provided with floating paddies, as shown in lig. 3,211'1, sheet 2, which, being attached or hinged by their outer ends on the rear side of the revolving arms, will lioat loosely as the armsdesccnd, but will rest against thenras they ascend, andreceive the impulse of the ascending current of ebullition, so as to be efficient propellers in a boiler of large diameter. Their elicieucy may be increased by the addition ot' a steam-cap, s c, at the outer end of the arm, which will catch the bubbling steam as it ascends and discharge it as it passes the vertex oi' the circle. Each cubic l'oot oi' steamthus caught will add about sixty pounds to the torce ci' rotation.

The spiral arrangement of the Scrapers is not essential. It' they are set at the proper angle ou longitudinal Abars the result will be attained very well rapidly consumed, will render it dcsirablethat those brick, bauxite, or some other equally refractory subthe evaporating-tubes and ,boilers and the rapidity of This was a proper Two such bars will be entirely sutlcient for the scraping, and the remainder of the space may be used for the lichting propellers p ,p and the steam caps sc sc.

Ihe steam-caps should, of course, be close to the circumference of the boiler to collect steam, as the evaporation or boiling is effected by external'heat from the steam-spaces s s.

In the vertical boilers a single longitudinal scraper of moderate friction, like a wire brush, will be suicient, and may be propelled by the current ci' ebullition as cending exteriorly or descendingl interiorly.

Vanes like a windmill, or arranged in a spiral, may be located so as to be turned by the outer ascending or the inner descending current. The former is shown in tig. 4, sheet 2, aswell as the latter.

Fluid Currents.

The removal of salt vand prevention of its incrustation by Huid currents require that they should havea speed oi' about ve miles an hour. The most reliable method of producing any speed that may be required is bymeans f a pump. InV applying a pump toa boiler for this purpose it becomes necessary that the rapid current through the boiler should dow into an enlarged space, in which the salt may be deposited as the speed becomes diminished.

In Figure 5, sheet 2, the pump is combined witn'a concentric cylinder boiler, and the -current which' passes through the boiler passes into the salt-receptacle S R, which, having about fifteen times the sectional area of the channel which brings in the salt, reduces the speed of the brine to a rate that will allow the salt to be deposited.`

The ends only ofthe boiler'are shown in thedrawing, but in Figure 5 the proportions are more nearly illustrative, andthe arrangement-shown of a central steamtube and'one steam-space is that which will be found best adapted to high pressures-as the whole may be comprised in one foot diameter, witheloi'igation at discretion.

Thisy combination is especially adapted to vertical boilers, in using which the salt may be delivered into ,a receptacle at the upper end of the boiler, which will be Very convenient for'its removal, (see Figure 9", in which the upper salt-receptacle is attached to a boiler without a pump, receiving the salt from the ascendingi'nstead of the descending current.)

A rotary or centrifugal pump, as it would be less liable to obstruction by the salt, would be appropriate, and perhaps preferable.

The currentl of ebullition, however, may be suiicient, if the length of' the ascending column be suflciently increased, to prevent all incrustation. I therefore propose a system of Y l Accelerator Channels,

Forthe removal of the salt, constituted as follows:

At the upper end of a vertical or the end of a horizontal boiler I add a vertical channel, -iu which the boiling brine and steam-bubbles nlay ascend, and prolong it downward from its summit, as at A C D C, theascending and descendingv channels of Figures (i and 7, ending' it inthe enlarged salt-receptacle S R, from which, through the neck N, the brine returns to the boiler and the circulation is regularly maintained.

ln the horizontal boiler, a horizontal partition, to separate the incoming and outgoing currents is expedient, as shown in iig. 7, but this may be dispensed with by connecting the receptaclewith one end of the boiler, andthe ascending channel with the other, as shownin iig. 7.

The heatin arranvement of the boiler fig; 6 ma g. o 7 i y be either la cylindrical condenser, as shown, ora-collectionof vertical tubing, as shownin my patent of July, or an external steam-jacket, or a combination of these methods, or a concentric combination, as Shown in tig. 5.

I simply propose to add an ascending and descending channel (running to a receptacle) to any plah of boiler, and, as it may sometimes be preferable not to have the channels exterior, I propose in that case to run them within the boiler, as in Figures S and 9.

In iig. 8 I show a current of ascent producedfby the vertical boiling-tubes bt bt, located in a circle between the cylindrical partition 1m pa, and the shell of the boiler, which is heated. by a steam-jacket and doubles the-force of ebullition, which, being confined in a narrow circular channel, makes a very rapid ascending current, the rapidity of which depends on the temperatures used andl the length of the ascending column'. I propose to give this column a length ot' fifteen to thirty feet, (with arrangements to diffuse the steam uniformly through 'the column of \vater,) to make it a powerful accelerator channel.

The evaporating surfaces need not extend more than one-half or two-thirds of the vertical length of the channel. 'l'.he descending'chamiel in this latter case isformed by the cylindrical partition that stands interior to the boiling-tubesand the lower end of the boiler is enlarged into a huge salt-receptacle, as shown in the drawing.

In iig. 9 the same idea is developed, with a slight moditication. The elongated boiler, with abulbous enlargement of its lower end, has its boiling-tubes and ascending currents in the interior, audits descending current in the exterior, circle.

Above thc upper extremity of the boiling-tubes the ascending and descending channels are reduced in diameter, and may be prolonged` indefinitely, to give force to the ascending current.

Anelongation of twenty or thirty feet, above boiling-tubes 500 or SOOliotter than the surrounding brine, would make a current of great power, and to produce its full eiiect the descending channels should be larger than the ascending.

The O'irculctor.

The foregoing methods of mechanical removal by scraping or friction, and 4uid removal by pump-currents or ebullition-curreuts, will overcome the most obstinate ditlculties of incrusting brines; but in some cases, from 'the nature of the evaporating-surfaces, but little mechanical force may be required, and in such cases the structure `which I call a ciiculator, Figure 13, will eiiect all that is necessary. 'This consists of a series oi' inclined planes 'ip t'p, lig. 13, whichmay he combined with any suitable form of steam-heater, and a nearly horizontal plane, lp, in combination, by which the boiling brine is thrown in'a current above to the right end of the boiler, and passes below to the lett end, beneath the plane lp.

At each end a pocket, po po, receives the falling salt from the quiet part ot' the current. lIhe salt-v carrier (of .my tirst patentlshould be attached to these pockets to remove their contents 'as often as necessary.

Removal by Solution..

- as one, making atwin series.

the order A B 0 D E F G, or from the boiler G, in the order G F E D C B A.

The vacuum-evaporator H will connect with the last or G for its steam, or, when the order is reversed, will connect with A.

The double series of steam-pipe connections, as shown in the drawing, renders it easy, by closing one set, to reverse the action by sending steam from the furnace to operate on the other line. In this arrangement, the boiler at each end of the series should correspond, and-be adapted to the highest pressure by f having a smaller diameter, while the diameter' may increase to the middle of the series, which sustains the least pressure.

The arrangements of theevaporators to remove the salt by the salt-carriers will, oi' course, require to be attached to a corresponding number (say three) at 'each end of the series, and the connections with thc pressure-chamber will have to be reversed.

The connection of the concen'trators by the pipe clp, as shown in my patent, will require to be closed by a cock, and the devices'by which the evaporators are supplicd'from the pressure-chamber will bave'tobe' attached to each boiler that may be required to act as an evaporator. In vother words, each boiler will require double connections with the pressure-chamber,v to enable it to actalternately in different capacities.

. It will also be expedient to prolong the neck which communicates to the salt-carrier below the-conical valve, andv introduce a. large stop-cock, as better adapted than the conical valve to sustainingv high pressure.

The exterior steam-jacket may or may not be retained in the entire series. The necessity for its use will be in proportion to the number of the series; a very short series would not require it.

. Twin Series.

. Another mode nfl-reversing the action to dissolve incrustation is by establishing two exactly corresponding series, which are connected together and act In this arrangement, i'g.'2, sheet 2, each boiler of the series A (which may be of any required number, say from ve to eight or ten) is connected with the corresponding boiler ofthe similar series B, byfa brine-pipe, bp, and all the boil ers of the series A act as coucentrators, while all of the series Bact as evaporators, and have the salt-car- `rierattachments sc, to remove the salt as formed.

The passage ot' the brine from A to B maybe governed by a oat, adj usted to open the valve when the brine is nearly. saturated;l or it may be left entirely free, so that the boilers will maintain about the same level, and the amount supplied to each will be determined by its consumption or evaporation.

The amount drawn by B from A will be about onehalf of the amount supplied to A to keep it full, and as it will come from the bottom of A, will be of the,I most concentrated brine.

The fresh brine supplied to A at its upper end will remain above until concentrated, and the saturated brine will naturally collect at the bottom and pass over to B as fast as the evaporation in B lowers the level of its brine.

Whenever the saline incrustation of B requires removal, the operation is changed `by simply attaching.

.the supply-pipes for brine to B and detaching them from A. -It' a Gilford injector is used, that 'of A is closed byits cocks, and that of B is opened, so that the supply of freshy brine to B concentrates in it and passes.. as concentrated to supply the demand of A. rlhus a mere pipe-connection of the corresponding boilers'is sucient, and the pressure-chamber is unnecessary.

' rlhe twin series may be adapted to urines ci any l degree of dilution by increasing the proportional size and evaporating power cr the iirst series that receives the brine. This dsproportion will render it necessary that the reverse action should be only for the shortest time necessary, to remove incrustation. For brines as weak as sea-water a triple or quadruple series mightj be used, developing salt only in the last series.; or theseries might be even more numerous. -ln reversing such a series, we need a salt-collecter only for the,

boiler at each endA g The principle developed by these plans is, that the gradual consumption oi' caloricby successive transfers, lowering its intensity from boiler to boiler, need not be accompanied by any corresponding concelnira-V tion or the brine as 'proposed in my patent, but that the' succession of boilers'oi' .different temperatures may .operatel on brine of the same grade, and the concentration may take place not by passing from a boiler to another of lower temperature, but bypassing from series to series at similar temperatures,f and that the series may be twin, triple, quadruple, qnintupl'e, or

more numerous, and may be strictly equal', or may be very unequal, as when a twin series operates on very weak brine, and the .conccntrator-series may be tive or ten times as large as that which usually acts as the evaporator series.

The peculiar process which this improvement de-` .velops is that of operating a series ot' transferringboilers (by which -I mean a series operating in connection on the same caloriclcn brine of the same grade, and operating combined series in connection o n brines. successively concentrated from eachseries to the next.

The transferring series, operating on the same calorie, may be properly called a monothermal series, y and when arranged as shown in tig. 1,'second sheet, becomes avreversible `monothcrmal series. 'llhe arrangement shown in iig.` 2, sheet .l, constitutes the combined parallel series, each member of whiclris a single monothermal series. vy thus disconnecting the serial concentration of brine from the ,serial transfer of heat we gain a better control of incrustation and thegreater simplicity of structure,l which is displayed in fie. 2. The construction of quadruple and quintuple parallel series gives a peculiar adaptation to weak brines.

Forms of Boilers. The concentrator-boilers, which were delineated in my patent without ,variation from the single type, f given for the whole machine, may be more advantageously throw-n int-o a horizontal position in many cases,v and when thus arranged the heaters may be modified as follows: The condensing-tubes should be arranged as compactly as possible in the lower two-thirds ot' the boiler, and each end inserted in a steam-space, one ot' which supplies the steam and the other removes the water of condensation.

For extreme high pressures in the first boiler we may use either the concentric boiler, shown in figs. 5

land 5^, or the compound tubular, shown in Figures 10 and 11. In iig. 10 a main horizontal pipe has a series ot small circular pipes connected withl it, as shown. In

tig. 11 the main pipe,which may be fourvortive inches in diameter, has a largenumber of' short, straight pipes inserted in its circumference, so as to bristle in every direction, like a porcupine, and fill the interior space of the boiler. Each of' these forms gives a large amount ci' surface and sustains a very high pressure. The condensed steam easily escapes by w t, the water-tube at one end.

For a moderate pressure, as in the fourth boiler of the series, the hash-heater, Figure 12, is desirable, as it gives a large amount of surface, and may be made of cast-iron. It is simply a main pipe ot' four or ive inches diameter internally, with flask-formed vessels connected with it by theirl necks, as shown.

.The last of the evaparator series or vacuum evaporator should be constructed so as to evaporate from shallow vessels and condense by the cold brine, as shown in Figure 16, in which several long, shallow pans are superimposed on each other tomake a compound evaporator.

lhe steam-spaces s s, at the bottom oi' each pan, under its whole length, receive their steam at one end, and at the other discharge their condensation bythe pipes w t, which may be assisted by a pump.

'The vapor arising from these pans, at a temperature between 130 and 1600, passes by the tubes s p2 into the tubes of the condensing-vat c c, from which it is pumped, there being'an interval ot' about 900 of temperature between the condensing-vat and the vacnum evaporator.

I propose to use two other forms of boilers, designed for operating on a smaller' scale, and adapted to working in a concentrator and evaporator series, or to being det-ached and used separately.

Figure 15, the tilting boiler, is simple in construction, and being supported and turning on two pivots, p p, it -is easily 'turned over to' empty its contents. rlwo small vertical boilers are iitted into each other', so as 'to-leave a steam-space between, and are iirml y fastened by their'ilanges together.

The cap of the boiler c a is fastened by its anges to the lower part by means of a yoke and screw, y s, as heretofore explained, for the connection ofthe saltcarrier. It receives steam at 51),'aud discharges the water of condensation at w t. ,l

The brine is supplied by the pipe bp,'which extends from the inner through the outer vessel, and the steam of the boiling passes off by s p2. It is thus adapted .to work in the series, or detached. Y The mushroom heater' boiler, Figure 14,has the same simplicity and general objects, and may be used in ther series, or detached. Its interior is occupied by .hollow vessels, screwed together' by their necks, of mushroom shape, which rapidly condense the steam coming in by `the pipe s t and discharge the water oi' condensation by w t. r

Doors d d are'provided oneach side of these pipes to discharge'the contents, and a brine-pipe opening is made in the lflange at b1), where the top is fastened, as in the tilting boiler.

Preventive Arrangements.

To diminish incrustation I propose to enamel the evaporating surfaces use d with an enamel composed ci? sand orpnlveriaed quartz, ten parts; cryolite, ten;

3. 'lhe combination of the channels A C D C in a concentric manner, as shown in iigs. 8 and 9, and their prolongation through the boiler.

4. The combination, with a salt-boiler, of the circulator and salt-pocliets, iig. 13, being the series of inclined planes t p i p and l 11, to establish currents between the pockets po po.

5. The combination, with a close salt-boiler, of the revolving spiral "scraper, iig. 3, to effect the removal of salt while under pressure.

6. rlvhe combination, with a revolving scraper for a vclose salt-boiler, oi' the propelling floats p p1) and the steam-caps s c s c, substantially as described, for the purposes mentioned.

7. The combination, with a vertical salt-boiler, oi the 'vertical rotary scraper, iig. 4., and the propellingpaddles p p p p, substantially as and for the purposes described.

8. The combination, with a monothermal series of boilers, of double steam-pipe connections, in such a manner as to make their serial action reversible, snb stantially asA described. p

V9. The combination of two or more monothermal series of boilers into combined parallel series, substan-V tially as described.

10. The combination, with a brine-boiler, of the compound tubular steam-heating and condensing structure, shown in iigs. 10, ll, substantially` as dcscribed.

11. llhe combination, with a brine-boiler, oi the flask-heater or condensingvessel, as shown in fig. 12, substantiallyas described.

brine-boilers, of` the compound vacuum evaporator, iig. 16, or equivalent structure-s, for vacuum evaporation by the heat of vapor.

13. The tilting boiler, iig. 15, substantially as described, for serial or detached use.

14. The brine-boiler, g.14.`, with the mushroom heater and serial connections, substantially as` de scribed.

15. The combination, with a brine-boiler, of a se ries of concentric cylinders, forming condensing steamheaters, igs. 5 and 5', substantially as described.

16. The combination of narrow descending smokechannels and ascending cold-air channels to effect the Icondensation of the vapor and recovery of the latent and sensible heatin the products oi' combustion.

17. The combination of the parallel ilattened airchannels t c, sliding upon a rack in'a smoke-chamber, to extract the caloric of the smoke, substantially as described.

155. The combination, with the flue which conveys the products of combustion, of the two inverting-cylinders o o, g. 4, sheet 1, and their appendages, the channels It a 1 2 3, for the recovery of heat and condensation of vapor by an upward current of cold air.

19. The method of transferring heat from a furnace by a concentrated solution of caustic soda or potassa circulated in tubes, or equivalent arrangements.

J. B. BUCHANAN.

Witnesses:

F. W'. HOWARD, A. M.' S'rour, Jr.

12. The combination, with a mouothermal series ot' 

